Past sorption studies evolved with time from generic, to waste specific, to empirical waste-specific/site-specific studies. Current sorption studies are site specific based on a radionuclide transport soil prop erties model (PERCOL). Radionuclide sorption is treated in the model PERCOL by the use of labora tory developed empirical/statistical equations that predict sorption as a function of groundwater chem istry. Analyses involve average sorption equations measured for 21 identified Hanford Separation Areas sediment types. Statistical analysis of 90Sr, I37Cs, and 60Co sorption for the 21 sediment types required 63 sorption equations.